焦化厂多环芳烃污染场地的环境评价实证研究

通过实地调查某焦化厂污染场地污染现状，结果表明：该场地土壤和地下水以多环芳烃（PAHs）有机类污染为主，土壤中苯并（仅）芘和多环芳烃污染以1．5m以内表层土污染为主，随着深度的增加浓度逐渐降低，弱透水层表现出良好的阻隔作用。沿着地下水流动方向，地下水中多环芳烃浓度逐渐降低，经过约400m的迁移，由17296μg／L降至111μg/L；苯并（α）芘经过200m的迁移，由18．3μg／L降至0，地下水流动导致污染物在包气带横向扩散。1号孔、3号孔和4号孔所在地表层土壤中苯并（α）芘的单个污染物的致癌风险分别为0．0278、0．0209和1．496，远远超出可接受水平，因此上述孔位所在地附近表层土壤需重点治理。

An Empirical Study on Environmental Assessment for Contaminated Site of a Coke and Chemicals Factory by Polycyclic Aromatic Hydrocarbons

Field survey of soil contamination in a coke and chemical factory was carried out and the result showed organic contamination occurred in soil and groundwater of the site mainly due to PAHs contaminants. Benzo （α） pyrene and PAHs were the dominant contaminants in soil 1.5m beneath the topsoil. Concentrations of both contaminants decreased with the depth increase and the aquitard act as good barier for the transportation of contaminants. Concentrations of PAHs decreased from 17 296 μg/L to 111 μg/L by 400m migration along the flow direction of groundwater. Concentrations of Benzo （α） pyrene reduced from 18.3 μg / L to 0 by 200m migration. The groundwater flow induced the lateral diffusion of contaminants in the vadose zone. The cancer risks of Benzo （α） pyrene in topsoil located around No. 1 hole, No. 3 hole and No. 4 hole were 0. 0278,0. 0209 and 1. 496 respectively far beyond the acceptable level. So the topsoil located around the holes we mentioned above need to be remediated as a primary.